Though I agree that some of Warne's success is undoubtedly down to who was at the other end a lot (perhaps the same could be said of McGrath's?), Warne's wickets didn't just come from people hitting out against him in frustration, did they? He took the wickets of people trying to bat carefully against him, often when bowling round the wicket at right handers.
It's not the number of wickets taken by Warne that puts him in list of top talents for me but the fact that I haven't seen his like playing test cricket before and can't envisage seeing it again.
McGrath, whilst a top class bowler, sits in the same kind of group as Donald, Hadlee, Ambrose, Walsh, Akram and so on for me.
All the ones on that list are still slower to 350 wickets than Steyn. Warne is the greatest spinner of all time. Mcgrath whilst being a huge part of Australia's success will never be rated as one of the all time greats imo. He's like Pollock!
Mcgrath sr 51.9 Steyn sr 42 Donald sr 47. That to me is the most important stat when it comes to bowling.